WAEC Chemistry 2025 Paper

Concept:The longest chain must include the $-\mathrm{OH}$ group, and the chain is numbered from the end that gives the $-\mathrm{OH}$ carbon the lowest possible number.Explanation:The compound $\mathrm{CH_3CHClCH_2OH}$ has a continuous chain of three carbon atoms, so the parent alkane is propane.The $-\mathrm{OH}$ group is attached to the terminal carbon of the $\mathrm{CH_2OH}$ end.Number the chain from this end so that the alcohol carbon is carbon 1.The chlorine atom is on the next carbon, which becomes carbon 2.The substituent is chloro, and the alcohol gives the suffix "ol".Therefore, the correct IUPAC name combines the positions and functional groups as 2-chloropropan-1-ol.Answer:D. 2-chloropropan-1-ol